1. Technical Field
The present invention relates to a method and structure that provides a battery within an integrated circuit for providing voltage to low-current electronic devices that exist within the integrated circuit.
2. Related Art
An integrated circuit, which may include a semiconductor chip, comprises electronic devices on a bulk silicon wafer, and metallic wiring patterns which conductively couple the electronic devices, resulting in formation of electrical circuits. “Conductive” and like words means “electrically conductive” herein, unless otherwise stated. The electronic devices include field effect transistors, bipolar transistors, diodes, etc. The metallic wiring patterns include conductive wiring lines, metal-plated vias, etc. In integrated circuits, the metallic wiring patterns are multi-layered, wherein each layer includes intra-layer metallic wiring patterns embedded within insulative material such as dielectric material. Intra-layer metallic wiring patterns of a given layer may be conductively coupled to intra-layer metallic wiring patterns in one or more other layers, as well as to the electronic devices.
The electronic devices of the integrated circuit require bias voltages and reference voltages, which are supplied by conventional or standard voltage sources. A conventional or standard voltage source includes a battery or the like which is readily commercially available. For particular integrated circuit applications requiring nonstandard bias and nonstandard reference voltages, conventional or standard voltage sources may be inadequate. A nonstandard bias or nonstandard reference voltage is any voltage not included in the voltages supplied by the standard voltage source.
There is a need for a method and structure to supply nonstandard bias voltages and nonstandard reference voltages in accordance with special requirements of particular integrated circuits.